Am I a GC?

Am I a GC ? or DC ?

The answer is fun to find out whether a Domain Controller is Global Catalog server which has several ways to find out


Open Active Directory Users and Computers –>Right click on Domain –> select Change Domain Controller

DSA-change DC dsa-change dc2

II. ADSIEdit Output:

There are three important attribute types which are important in AD

  • System Only
  • Constructed and
  • Backlinks

Constructed attributes are most important attributes in AD which provides advance interpretation of AD operations. One such attribute is msds-isgc, this attribute identifies the state of Global Catalog Server.


III. DSQuery

Global catalog status can be viewed using DSQuery tool as shown below


IV NLTest:

Global Catalog status can be found using NLTest tool through Flags Status as shown below




One other tool to view Global catalog status is by using LDP tool. Please note that Constructed Attribute cannot be viewed using standard LDP interface instead, a search should be made to view the status of a Global Catalog Server as shown below.

ldp -isgc

Other tools include PowerShell or DS API requires DN path to search for the value.


DNS Default Server : unknown

DNS Default Server: Unknown , this is the most common message Users see when they enter nslookup. This message means the DNS server which is configured on the client is not able to resolve itself / there is no pointer record configured for the DNS server.

DNS Server Unknown

To resolve the error, DNS administrator should ensure, there is an associated PTR record registered in the zone’s reverse lookup zone and test the nslookup command which should populate the DNS server name